There was one English teacher at my school who was like this. Objectively, in hindsight, he was really nothing special to look at, but he dressed very sharply (I remember one lesson when he came in wearing a new suit and jaws literally dropped) and was very knowledgeable and charming. I was very keen and well-behaved and he obviously liked me as a pupil, and rumours started that it was more than that, though they were only ever light-hearted. Nothing would ever have actually happened, but it was entertaining for people to imagine...